<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport"
        content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>按钮点击一次后失效</title>
</head>
<body>
  <button>确认</button>
  <script>
    var btn = document.querySelector('button')
    btn.onclick = function () {
      this.disabled = true
    }
  </script>
</body>
</html>